According to different molding methods, the types of pl […]
According to different molding methods, the types of plastic processing molds corresponding to different process requirements can be divided, mainly including injection molding molds, extrusion molding molds, blister molding molds, and high foaming polystyrene molding molds. Plastic mould
1.Plastic injection (plastic) mold
It is mainly a molding mold most widely used in the production of thermoplastic products. The corresponding processing equipment for plastic injection molds is a plastic injection molding machine. The plastic is first heated and melted in the heating barrel of the injection machine, and then the screw of the injection machine. Or, when the plunger advances, it enters the mold cavity through the injection system of the injection nozzle and the mold, and the plastic is cooled and hardened to form the product. Its structure is generally composed of molded parts, casting system, guide parts, push-out organization, temperature control system, exhaust system, support parts and other parts. The materials used are generally plastic mold steel modules. Commonly used materials are mainly carbon structural steel, carbon east-west steel, alloy east-west steel, and high-speed steel. The injection molding processing method is generally only applicable to the production of thermoplastic products. The plastic products produced by the injection molding process are very wide. From daily necessities to various types of complex machinery, electrical appliances, transportation parts, etc., are formed using injection molds. It is the most widely used processing method in the production of plastic products.
2. Plastic compression molding molds include two types of structural molds: compact molding and injection molding. They are a type of mold mainly used for molding thermosetting plastics, and the corresponding equipment is a pressure molding machine. Compact molding method According to the characteristics of the plastic, the mold is heated to the molding temperature (generally 103 ° -108 °), and then the measured compression molding powder is placed in the mold cavity and the feeding chamber, and the mold is closed. It is softened and viscous. After a certain period of time, it is cured and shaped to become the desired product shape. The difference between injection molding and compact molding is that there is a separate feeding chamber. The mold is closed before molding. The plastic is preheated in the feeding chamber and is in a viscous flow state. Under the effect of pressure, it is adjusted into the mold cavity and hardened. Tightening molds are also used to mold certain special thermoplastics, such as hard-to-melt thermoplastics (such as polyvinylidene fluoride) blanks (cold compression molding), resin lenses with high optical functions, slightly foamed nitrocellulose steering wheels, etc. . The compression mould is mainly composed of a cavity, a feeding cavity, a guide structure, a pushing part, a heating system and the like. Injection molds are widely used in packaging electrical components. The materials used for making compression moulds are basically the same as those for injection moulds.
3. Plastic extrusion molds are used to form a type of mold that produces continuous-shaped plastic products, also known as extrusion heads. They are widely used in pipes, rods, monofilaments, plates, films, wire and cable coatings, and other materials. Processing of profiles, etc. The corresponding production equipment is a plastic extruder. Its principle is that solid plastic is melted, plasticized under the conditions of heating and screw rotation and pressure of the extruder, and made into a die with a specific shape to have the same cross-section as the shape of the die. Continuous plastic products. The main materials for its production are carbon structural steel, alloy things, etc. Some extrusion molds are also inlaid with wear-resistant materials such as diamond on parts that require wear resistance. The extrusion process is generally only applicable to the production of thermoplastic products, and its structure is significantly different from injection molds and compression molds.
4. Plastic blow mold is a mold used to form hollow products of plastic containers (such as various packaging containers such as beverage bottles and daily chemical supplies). The form of blow molding is mainly extrusion blow molding according to the principle of the process. , Injection blow molding hollow molding, injection stretch blow molding hollow molding (commonly known as "injection stretch blow"), multilayer blow molding hollow molding, sheet blow molding hollow molding, etc. The corresponding equipment for blow molding of hollow products is generally called a plastic blow molding machine. Blow molding is only suitable for the production of thermoplastic products. The structure of the blow mold is relatively simple, and the materials used are mostly made of carbon.
5. Plastic blister mold is a mold for forming some simpler plastic products with plastic plates and sheets as the material. The principle is to use a vacuum blooming method or a compact air molding method to fix it on a concave or convex mold. Plastic plates and sheets are deformed under the condition of heating and softening and are pasted on the cavity of the mold to obtain the required molded products, which are mainly used in the production of some daily necessities, food and toy packaging products. Due to the low pressure during molding, the mold material is mostly made of cast aluminum or non-metallic materials, and the structure is relatively simple.
6. The high-foaming polystyrene molding mold is a mold that uses expandable polystyrene (bead material composed of polystyrene and foaming agent) to form foam packaging materials of various shapes. The principle is that polystyrene can be steam-formed in the mold, including two types of simple manual operation mold and hydraulic straight-through foam plastic mold. It is mainly used to produce industrial packaging products. The materials for making such molds are cast aluminum, stainless steel, bronze, and the like.